Bump deps, add decorators support, update Vite config

Upgrade multiple dependencies (Cloudflare packages, ai/sdk packages, vite, @vitejs/plugin-react, wrangler, etc.) and regenerate package-lock.json. Add src/decorators.ts and install @babel/plugin-proposal-decorators and @rolldown/plugin-babel to enable decorator support. Update vite.config.ts to accommodate the new build/plugin changes and compatibility with updated toolchain versions.

Author: threepointone